The present invention relates to a personal identification system which can be utilized for a bank transaction processing system or an entrance and exit gate control system.
Only one magnetic card such as cash card (this will be called "card" hereinafter) is issued to a single user. However, the ordinary bank transaction processing system does not matter who is using a particular card and, thus, there is a danger of a fraudulent use of a card if the card is lost or copied.
Therefore, conventionally, a cryptographic number known only by the original owner of a card was predetermined, and the personal collation was made at the time of use of the card on the basis of an input of the cryptographic number by the user.
However, according to this kind of the identification system, there is such a problem that the owner of a card must be memorize a particular number (cryptographic number). In addition, there is another problem that the number of digits of a cryptographic number increases as the number of cards issued becomes larger, so that it becomes more difficult to memorize a cryptographic number. These problem are created because the combination of digits in a numeral is relatively complicated as information and it is not easy to memorize a numeral because of its inherent character.